package com.design03_behavioral.pattern13_observer.example01;

/**
 * @ClassName Subject
 * @Description 抽象目标类
 * @Author zhangjunhao
 * @DATE 2023/9/6 21:26
 */
public interface Subject {

    void attach(Observer observer);
    void detach(Observer observer);
    void notifyObservers();

}
